
# is 或 in
"""
is : 判断两个对象的引用是否一致
in :  判断一个元素是否在另外一个元素中
"""

a = 10
b = 10
if a is b:
    print("hello world")
else:
    print("你好，中国")

c = "hello world"

if "hello" in c:
    print("包含了hello")
else:
    print("不包含")